Center for Behavioral Science and Mental Health, Istituto Superiore di Sanità, Rome, Italy; Faculty of Psychology, International Telematic University "Uninettuno", Rome, Italy.
Center for Behavioral Science and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
Prog Neuropsychopharmacol Biol Psychiatry. 2020 Jun 8;100:109886. doi: 10.1016/j.pnpbp.2020.109886. Epub 2020 Feb 8.
The Naples High-Excitability (NHE) is a validated rat strain to model for a mesocortical variant of Attention Deficit Hyperactivity Disorder (ADHD). NHE rats' brains have a tuned-down cortical and a potentiated limbic loop (Zoratto et al., 2017). ADHD and comorbid pathological gambling (PG) involve similar deficits of prefrontal-striatal dialogue. This work aimed to understand if NHE rats (compared to normal random-bred rats, NRB) can be a useful model for gambling vulnerability in ADHD. Experiment 1 evaluated gambling proneness in NHE rats, namely attraction/avoidance in nose-poking for a "Large & Luck-Linked" (LLL) reward (versus a "Small & Sure" one, SS), when the probability of LLL delivery was progressively reduced. Experiment 2 assessed (by phMRI) differential responsivity of ventral (vStr) versus dorsal (dStr) striatum following a methylphenidate (MPH, 4 mg/kg I.P.) challenge. In NHE rats, reduced attraction by secondary cues (associated with uncertain, rarefying LLL delivery) comes along with little or no activation of dStr and enhanced activation of vStr by MPH. Together, such evidences from NHE rats indicate distinctive roles of ventral (enhanced value given to actual primary reward) and dorsal (lower encoding of repeated stimulus-reward associations into a habit) striatum. In conclusion, the dynamics of reward systems could link an attention deficit with a decreased vulnerability to pathological gambling.
那不勒斯高兴奋（NHE）大鼠是一种经验证的大鼠品系，可用于模拟注意力缺陷多动障碍（ADHD）的中皮质变异。NHE 大鼠的大脑皮质和边缘回路的调谐降低（Zoratto 等人，2017 年）。ADHD 和共病病理性赌博（PG）涉及前额叶纹状体对话的类似缺陷。这项工作旨在了解 NHE 大鼠（与正常随机繁殖大鼠 NRB 相比）是否可以成为 ADHD 赌博易感性的有用模型。实验 1 评估了 NHE 大鼠的赌博倾向，即在“大而与运气相关”（LLL）奖励（与“小而确定”奖励 SS 相比）的鼻戳中吸引/回避，当 LLL 交付的概率逐渐降低时。实验 2 通过 phMRI 评估了腹侧（vStr）与背侧（dStr）纹状体在哌甲酯（MPH，4mg/kg IP）挑战后的反应性差异。在 NHE 大鼠中，与不确定、稀少的 LLL 传递相关的次要线索的吸引力降低，同时 dStr 的激活很少或没有，而 MPH 增强了 vStr 的激活。综上所述，NHE 大鼠的这些证据表明腹侧（增加对实际主要奖励的价值）和背侧（将重复刺激-奖励关联编码为习惯的能力降低）纹状体的作用不同。总之，奖励系统的动态可能将注意力缺陷与降低病理性赌博的易感性联系起来。
